IOS calculates how long the last date is now, such as xx hours ago and xx minutes ago, iosxx

IOS calculates how long the last date is now, such as xx hours ago and xx minutes ago, iosxx
/** * Calculate the distance between the last date and the current time * * @ Param lastTime the last date (corresponding to the format) * @ Param format1 last date format * @ Param currentTime recent date (corresponding to the format) * @ Param format2 Latest Date Format * * @ Return xx minutes ago, xx hours ago, xx days ago */+ (NSString *)timeIntervalFromLastTime:(NSString *)lastTime                        lastTimeFormat:(NSString *)format1                         ToCurrentTime:(NSString *)currentTime                     currentTimeFormat:(NSString *)format2{    // Last time    NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc]init];    dateFormatter1.dateFormat = format1;    NSDate *lastDate = [dateFormatter1 dateFromString:lastTime];    // Current time    NSDateFormatter *dateFormatter2 = [[NSDateFormatter alloc]init];    dateFormatter2.dateFormat = format2;    NSDate *currentDate = [dateFormatter2 dateFromString:currentTime];    return [Utilities timeIntervalFromLastTime:lastDate ToCurrentTime:currentDate];} + (NSString *)timeIntervalFromLastTime:(NSDate *)lastTime ToCurrentTime:(NSDate *)currentTime{    NSTimeZone *timeZone = [NSTimeZone systemTimeZone];    // Last time    NSDate *lastDate = [lastTime dateByAddingTimeInterval:[timeZone secondsFromGMTForDate:lastTime]];    // Current time    NSDate *currentDate = [currentTime dateByAddingTimeInterval:[timeZone secondsFromGMTForDate:currentTime]];    // Time Interval    NSInteger intevalTime = [currentDate timeIntervalSinceReferenceDate] - [lastDate timeIntervalSinceReferenceDate];     // Second, minute, hour, day, month, and year    NSInteger minutes = intevalTime / 60;    NSInteger hours = intevalTime / 60 / 60;    NSInteger day = intevalTime / 60 / 60 / 24;    NSInteger month = intevalTime / 60 / 60 / 24 / 30;    NSInteger yers = intevalTime / 60 / 60 / 24 / 365;     if (minutes <= 10) {        return@ "Just now";    }else if (minutes < 60){        return [NSString stringWithFormat: @ "% Ld minutes ago",(long)minutes];    }else if (hours < 24){        return [NSString stringWithFormat: @ "% Ld hours ago",(long)hours];    }else if (day < 30){        return [NSString stringWithFormat: @ "% Ld days ago",(long)day];    }else if (month < 12){        NSDateFormatter * df =[[NSDateFormatter alloc]init];        df.dateFormat = @ "M-d";        NSString * time = [df stringFromDate:lastDate];        return time;    }else if (yers >= 1){        NSDateFormatter * df =[[NSDateFormatter alloc]init];        df.dateFormat = @ "Yyyy-M-d";        NSString * time = [df stringFromDate:lastDate];        return time;    }    return @"";} Use:NSLog(@"\n\nresult: %@", [Utilities timeIntervalFromLastTime:@ "December 8, 2015"                                           lastTimeFormat:@ "Yyyy-MM-dd HH: mm"                                            ToCurrentTime:@"2015/12/08 16:12"                                        currentTimeFormat:@"yyyy/MM/dd HH:mm"]); The output result is as follows: